1. Field of the Invention
The invention is in the field of recovery plants for the recovery of water from the atmosphere.
2. Description of the Prior Art
German Pat. Nos. P 26 60 068.0 and P 27 52 748.6, incorporated herein by reference, describe water recovery plants in which an adsorbent layer is preferably arranged directly above a heat reservoir. In this manner nighttime air for adsorbing water is passed first through the heat reservoir and then through the adsorbent layer, and subsequently daytime air for desorbing moisture is passed first through the adsorbent layer and then through the heat reservoir. If necessary, the daytime air can be heated by solar radiation up to a temperature beyond the temperature of the outdoor air. Preferably the daytime air is supplied without intermediate conduits from the heat reservoir to the adsorber and conversely from the adsorber to the heat reservoir. Reference is also made to copending applications of the same assignee as herein, namely Mittex Aktiengesselschaft, for "Process and System for Recovering Water from the Atmosphere", Ser. No. 781,890, filed Mar. 28,1977, now U.S. Pat. No. 4,146,372 ; for "Process and Plant for the Recovery of Water from Humid Air", Ser. No. 963,647, filed Nov. 24, 1978, now U.S. Pat. No. 4,219,341 ; and for "Silica Gel of Improved Properties and Process of Making Same", Ser. No. 747,474, filed Dec. 6, 1976, now U.S. Pat. No. 4,148,864 ,the whole of which applications being incorporated herein by reference.
Recovery plants using such processes compete with other water recovery processes, e.g., sea water desalination, in terms of expenditure of investment, maintenance and operation. Indeed, the expenditure for the recovery of 1 liter of water by the above-described plants is substantially less as compared with the sea water desalination. Nevertheless such plants are still at a level which makes the plants attractive primarily for supplying only drinking water in countries located, for example, in the tropics. However, capital outlays with such plants are still too high for large scale recovery of water for use in irrigating and cultivating large desert areas.